scholarly journals Improving the Flame Retardancy of Bamboo Slices by Coating With Melamine–Phytate via Layer-by-Layer Assembly

2021 ◽  
Vol 8 ◽  
Author(s):  
Peng Lin ◽  
Yuchen Xu ◽  
Junfeng Hou ◽  
Xiaochun Zhang ◽  
Lingfei Ma ◽  
...  
Keyword(s):  
Flame Retardancy ◽  
Vital Role ◽  
Asia Pacific ◽  
Layer By Layer ◽  
Natural Polymer ◽  
Release Rates ◽  
X Ray ◽  
Lbl Assembly ◽  
Rich Natural Resource ◽  
Assembly Technology

Bamboo is a rich natural resource in the Asia Pacific, and it is widely used in the construction and decoration industry. Meanwhile, bamboo is an extremely combustible natural polymer material. Herein, the bamboo slices were treated with melamine and phytic acid using layer-by-layer (LBL) assembly technology to improve their flame retardancy properties. The morphology and chemical composition of untreated and treated bamboo slices were measured by scanning electron microscopy equipped with energy dispersive X-ray analysis and Fourier transform infrared spectra. The results showed that two-dimensional melamine–phytate (MP) nanoflakes were successfully formed and deposited on the bamboo surface. The deposition of the MP coating caused the earlier degradation of the bamboo to form char, according to thermogravimetric analysis. The peak heat release rates of the treated bamboo slices were reduced by more than 28% compared to those of the untreated ones. The MP coating promoted the formation of thermally stable char, which was responsible for the significant improvement in flame retardancy. Besides, the char layer with excellent thermal resistance performed a vital role in suppressing flame spread.

scholarly journals Correlation of Montmorillonite Sheet Thickness and Flame Retardant Behavior of a Chitosan–Montmorillonite Nanosheet Membrane Assembled on Flexible Polyurethane Foam

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 213 ◽  
Author(s):  
Peng Chen ◽  
Yunliang Zhao ◽  
Wei Wang ◽  
Tingting Zhang ◽  
Shaoxian Song
Keyword(s):  
Flame Retardant ◽  
Flame Retardancy ◽  
Sheet Thickness ◽  
Wall Structure ◽  
Layer By Layer ◽  
Lbl Assembly ◽  
Assembly Technology ◽  
Flexible Polyurethane Foam ◽  
Flexible Polyurethane ◽  
Different Thickness

Polymer–clay membranes constructed via the layer-by-layer (LbL) assembly, with a nanobrick wall structure, are known to exhibit high flame retardancy. In this work, chitosan–montmorillonite nanosheet (CH–MMTNS) membranes with different thickness of MMTNS were constructed to suppress the flammability of flexible polyurethane (FPU) foam. It was found that a thinner MMTNS membrane was more efficient in terms of reducing the flammability of the FPU foam. This was because such MMTNS membrane could deposit cheek by jowl and form a dense CH–MMTNS membrane on the foam surface, thus greatly limiting the translation of heat, oxygen, and volatile gases. In contrast, a thicker MMTNS constructed a fragmentary CH–MMTNS membrane on the coated foam surface, due to its greater gravity and weaker electrostatic attraction of chitosan; thus, the flame retardancy of a thick MMTNS membrane was lower. Moreover, the finding of different deposition behaviors of MMTNS membranes with different thickness may suggest improvements for the application of clay with the LbL assembly technology.

scholarly journals Fabrication of thermo-regulating cotton fabric with enhanced flame retardancy via layer-by-layer assembly

2021 ◽  
Author(s):  
Yunbo Chen ◽  
Xiangyu Zhu ◽  
Xiang Li ◽  
Bijia Wang ◽  
Zhiping Mao ◽  
...  
Keyword(s):  
Flame Retardancy ◽  
High Performance ◽  
Cotton Fabrics ◽  
Melting Enthalpy ◽  
Residual Carbon ◽  
Layer By Layer ◽  
Scanning Calorimetry ◽  
Infrared Thermal Imaging ◽  
Limiting Oxygen Index ◽  
Lbl Assembly

Abstract The lack of thermo-regulation functionality and high flammability of cotton fabrics greatly restrict their application in high-performance fields. Herein, we report a versatile layer-by-layer (LbL) assembly strategy for introducing to cotton fabrics a multilayered coating consisted of phase change microcapsules and ammonium polyphosphate, endowing them with thermo-regulating and flame retardancy. The coated fabrics were characterized by limiting oxygen index (LOI), scanning electron microscopy (SEM), thermogravimetry (TG), differential scanning calorimetry (DSC) and infrared thermal imaging. The fabric deposited with 20 bilayers (MCPM/APP-20) showed improved flame retardancy with a LOI of 24.4% and residual carbon of 34.24%. It also shows a melting enthalpy of 30.16 J/g, which transferred to a temperature difference of 6.4 ℃ compared with pristine cotton. The functional endowed by the LbL assembly was reasonably durable, with melting enthalpy and residual carbon of MPCM/APP-20 reduced to 17.14 J/g and 19.82% after 30 laundering cycles. These results suggest that LbL assembly was a convenient way for functionalization of cotton fabrics.

Few durable layers suppress cotton combustion due to the joint combination of layer by layer assembly and UV-curing

RSC Advances ◽  
2015 ◽  
Vol 5 (87) ◽  
pp. 71482-71490 ◽  
Author(s):  
Federico Carosio ◽  
Jenny Alongi
Keyword(s):  
Flame Retardancy ◽  
Uv Curing ◽  
Layer By Layer ◽  
Lbl Assembly ◽  
Layer By Layer Assembly ◽  
Innovative Solutions ◽  
Layer Assembly

In the last five years, Layer by Layer (LbL) assembly has proven to be one of the most innovative solutions for conferring flame retardancy to fabrics.

Layer-by-Layer Technology and Its Implications in the Field of Glucose Nanobiosensors

2015 ◽  
pp. 400-437
Author(s):  
Sharath P. Sasi
Keyword(s):  
Glucose Sensors ◽  
Layer By Layer ◽  
Fluorescent Biosensors ◽  
Glucose Levels ◽  
Non Invasive ◽  
Sensor Membrane ◽  
Lbl Assembly ◽  
Cause Of Deaths ◽  
History Of ◽  
Assembly Technology

Diabetes is the seventh leading cause of deaths in the US with almost 439 million people worldwide expected to be diabetic by 2030. The need for continuous, non-invasive monitoring is a top priority. Earlier devices that utilized electroenzymatic sensing technique were minimally invasive and had major pitfalls. Advancements in various non-invasive, especially fluorescence-based, sensing along with developments in LBL assembly have resulted in a new breed of micro/nanosensors that are implantable, reliable, reproducible, mechanically and functionally stable, responsive, and miniaturized. In this chapter, the authors discuss the history of glucose sensors, evolution over the past four decades, methods employed to detect glucose levels in fluorescent biosensors, and assays that can be fabricated on to the sensor membrane, immobilized into the membrane as multilayers, or encapsulated within micro/nanocapsules using LBL assembly technology. The authors briefly review the various materials available and currently implemented for fabrication of glucose biosensors using LBL assembly.

Layer-by-layer (LBL) assembly technology as promising strategy for tailoring pressure-driven desalination membranes

2015 ◽  
Vol 493 ◽  
pp. 428-443 ◽  
Author(s):  
Guo-Rong Xu ◽  
Sheng-Hui Wang ◽  
He-Li Zhao ◽  
Shui-Bo Wu ◽  
Jian-Mei Xu ◽  
...  
Keyword(s):  
Layer By Layer ◽  
Lbl Assembly ◽  
Promising Strategy ◽  
Assembly Technology ◽  
Pressure Driven

scholarly journals An eco-friendly and effective method to fabricate flame retardant cotton fabrics

2021 ◽  
Vol 293 ◽  
pp. 01022
Author(s):  
Xiaotao Zhang ◽  
Chunrong Zhou ◽  
Haifeng Pan
Keyword(s):  
Flame Retardancy ◽  
Fire Safety ◽  
Deposition Process ◽  
Cotton Fabrics ◽  
Environmentally Benign ◽  
Layer By Layer ◽  
Char Residue ◽  
Safety Properties ◽  
Lbl Assembly ◽  
Layer Deposition

To reduce the flammability of cotton fabrics, an environmentally benign, simple and effective method was proposed. Coatings composed of phosphoguanidine/ATMP/alginate were deposited on the surface of the cotton fabrics through layer-by-layer (LbL) assembly. FTIR spectra indicate that the layer-by-layer deposition process is successfully carried out on the surface of cotton fabrics. TGA suggested that LbL coating can significantly increase the char residue. The results of MCC and vertical flame tests showed that the LbL coatings can remarkably enhance the fire safety properties of the cotton fabrics and a higher concentration of ATMP (2 wt%) can bring better effect of flame retardancy.

scholarly journals Preparation of Layer-by-Layer Nanofiltration Membranes by Dynamic Deposition and Crosslinking

Membranes ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 20 ◽  
Author(s):  
Yan Liu ◽  
George Chen ◽  
Xiuli Yang ◽  
Huining Deng
Keyword(s):  
Membrane Surface ◽  
Deposition Process ◽  
Separation Performance ◽  
Layer By Layer ◽  
Good Separation ◽  
Membrane Performance ◽  
Polyelectrolyte Membranes ◽  
Lbl Assembly ◽  
Charge Property ◽  
Assembly Technology

In recent decades, the advancements in layer-by-layer (LBL) assembly technology have provoked increasing interest in the preparation of multilayer polyelectrolyte membranes with excellent performance. In the current study, a novel nanofiltration (NF) membrane was prepared by pressure-driven layer-by-layer (LBL) assembly of polyethylenimine (PEI) and polyacrylicacid (PAA) on a porous substrate with chemical crosslinking. The effect of deposition pressure on separation performance of the prepared membranes was studied. The surface morphology, hydrophilicity and the charge property of the dynamically-deposited membranes were compared with those prepared by static adsorption. The characterization results showed that dynamic deposition process resulted in a smoother membrane surface with improved hydrophilicity. The mechanism of water-path formation was proposed to interpret the effect of pressure on the membrane performance. Glutaraldehyde (GA) was used as a crosslinker to reduce the number of polyelectrolyte bilayers for obtaining good separation performance. The rejections of different inorganic salts of the dynamically-deposited NF membrane were also investigated.

Intumescent flame retardant finishing of polyester fabrics via the layer-by-layer assembly technique

2017 ◽  
Vol 29 (1) ◽  
pp. 96-105 ◽  
Author(s):  
Warunee Wattanatanom ◽  
Sireerat Churuchinda ◽  
Pranut Potiyaraj
Keyword(s):  
Thermal Properties ◽  
Flame Retardant ◽  
Flame Retardancy ◽  
Intumescent Flame Retardant ◽  
Layer By Layer ◽  
Polyester Fabrics ◽  
Content Type ◽  
Lbl Assembly ◽  
Assembly Technique ◽  
Coated Fabrics

Purpose The purpose of this paper is to investigate the potential use of the layer-by-layer (LbL) assembly as an intumescent flame retardant for polyester, cotton and their blended fabrics. Design/methodology/approach In this study, polyester (PET), cotton and their blends were applied with the flame retardant coating via the LbL assembly technique. The flame retardancy, melt dripping, thermal properties and morphology of coated polyester fabrics were then examined. Findings The scanning electron micrograph of uncoated and coated fabrics revealed that the LbL assembly coating on the fabric surface was successful. The assessment of the flame retardancy and thermal properties of the coated fabrics showed that the after-flame time and melt dripping during the vertical burning test decreased. The char residue at temperatures ranging from 450 to 800°C during thermogravimetric analysis was enhanced as compared with the uncoated fabric. Furthermore, the morphology of the char residual of coated fabrics was rougher and bulkier than the uncoated fabrics, suggesting the typical behavior of intumescence. Social implications The LbL technique generally uses much fewer chemicals, thus making this flame retardant finishing much more environmentally friendly. It is also expected that these fabrics will show better touch characteristics. These fabrics may be tested for their comfort compared to that of conventional coating to enable their use on an industrial scale. Originality/value This work demonstrated the ability to apply an effective intumescent coating on polyester, cotton and blend fabric. In order to maintain fabric handle property, the Lbl coating technique is also employed.

Effect of Calcium Ion Crosslinked Alginate Based Coating on Flame Retardancy of Polyester-Cotton Fabric

2017 ◽  
Vol 909 ◽  
pp. 145-150
Author(s):  
Ying Pan ◽  
Lei Song ◽  
Yuan Hu
Keyword(s):  
Cotton Fabric ◽  
Flame Retardancy ◽  
Calcium Ion ◽  
Layer By Layer ◽  
Char Residue ◽  
Spread Rate ◽  
X Ray ◽  
Assembly Method ◽  
First Time ◽  
Positively Charged

Bio-based and phosphorus-free coating was fabricated by layer-by-layer assembly method to obtain the flame retardant polyester-cotton fabric. For the first time, the modified polyester-cotton fabrics were prepared by utilizing positively charged polyethylenimine and negatively charged alginate together with subsequent crosslinking of calcium ion. Scanning electron microscopy and energy-dispersive X-ray demonstrated that the calcium ion crosslinked coating was successfully constructed on the substrate. The flame retardancy was investigated by horizontal flame test. The fire resistance of SA/PEI-Ca sample was enhanced significantly compared with the pure sample, as evidenced by the obvious reduction (16%) of flame spread rate and complete char residue.

r-GO/MWCNTs Nanocomposite Film as Electrode Material for Supercapacitor

2017 ◽  
Vol 751 ◽  
pp. 425-430
Author(s):  
Suttinart Noothongkaew ◽  
Orathai Thumthan ◽  
Pattanasuk Chamninok ◽  
Ki Seok An
Keyword(s):  
Current Density ◽  
Photoelectron Spectroscopy ◽  
Nanocomposite Film ◽  
Layer By Layer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lbl Assembly ◽  
Heat Treated ◽  
Reduced Graphene ◽  
Scan Rate

We synthesized a reduced graphene oxide (r-GO) multi-walled carbon nanotube (MWCNTs) nanocomposite film via layer by layer (LBL) assembly. This structure was prepared by vacuum filtration and heat-treated at a low temperature of 500°C. The morphology of the sample was determined by field emission electron spectroscopy (FE-SEM). The structural detail and the chemical analysis were characterized by using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), respectively. The cyclic voltammetry (CV) curve of r-GO/MWCNTs nanocomposite appeared nearly rectangular in shape. The current density (A/g) was gradually increased by increasing the scan rate of the voltage, as high as a scan rate of 500 mVs-1. At a current density of 10 mAg-1, the specific capacitance of the nanocomposite, estimated by galvanostatic (GA) charge/discharge measurement, is 150 Fg-1. These nanocomposites can be developed for supercapacitor electrodes.

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